Atoms of metal elements give away electrons in their reactions to form positive ions. The ions formed have a full outer electron shell, so are very stable.
Explanation:
To become stable, the metal atom wants to get rid of one or more electrons in its outer shell. ... Alternately, an atom that loses electrons becomes a positively charged ion (aka cations). The particles in an ionic compound are held together because there are oppositely charged particles that are attracted to one another.
